Effect of high radiation on roundleaf sundew (Drosera rotundifolia L.)

Mužic, Martina (2014) Effect of high radiation on roundleaf sundew (Drosera rotundifolia L.). Diploma thesis, Faculty of Science > Department of Biology.

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Abstract

Roundleaf sundew (Drosera rotundifolia L.) is a carnivorous plant that inhabits peat-bog areas which are rare in Croatia and in danger of extinction. Proposed mowing treatment of high vegetation prevents the disappearance of peat-bogs due to overgrowth, but also exposes shade-acclimated plants to high light conditions. The aim of this study was to determine the changes in photosynthethic efficiency well as content of photosynthetic pigments and phenolic compounds in shade-acclimated plants exposed to high light intensity radiation (700 ± 20 μmol photons m-2 s-1) for 5, 30, 50 and 100 h. Plants exposed to 5 and 100 h of high-light radiation were brought to the 7 days recovery under low light intensity. The control group of plants were grown under low intensity radiation (40 ± 20 μmol photons m-2 s-1) and represented shade-acclimated plants. The sudden exposure of shade-acclimated plants to high light intensity decreased the fluorescence-based maximal quantum yield of PSII and rate of electron transfer, but increased the value of non-photochemical quenching. Following high light exposure the plants have reduced the chlorophyll content in tissue, but increased carotenoids content as well as content of total phenols, tannins, flavonoids and anthocyanins. These results suggest that the exposure to high light intensity led to an overload of the photosynthetic apparatus and photoinhibition. However, acclimatization of plants was also observed because it is expected that the lower chlorophyll content would result in reduced energy absorption while increased carotenoids could dissipate excess energy thus protecting photosynthetic apparatus from excess light. In addition observed increase of phenolic compounds would protect plants from oxidative stress and/or further reduce the absorption of excess light energy.

Item Type: Thesis (Diploma thesis)
Keywords: light stress, fluorescence of chlorophyll a, photosynthetic pigments, phenolic compounds, reactive oxygen species, sundew
Supervisor: Tkalec, Mirta
Co-supervisor: Babić, Marija
Date: 2014
Number of Pages: 49
Subjects: NATURAL SCIENCES > Biology
Divisions: Faculty of Science > Department of Biology
Depositing User: Silvana Šehić
Date Deposited: 13 Nov 2014 11:19
Last Modified: 13 Nov 2014 11:19
URI: http://digre.pmf.unizg.hr/id/eprint/3255

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